When I got my 30 gallon aquarium, I had trouble finding the “perfect” filter for it. Finally, I came across the Fluval 204 canister filter that pumps about 180 gallons of water an hour.
It has worked very well for me: it is pretty easy to maintain, really keeps the tank clean, and there is a wide variety of media to choose from.
The 204 model has 3 sections. I have Filter Floss in the bottom, carbon in the middle, and bio max in the last one. The bottom receives the dirtiest water, so put your mechanical filtration there.